Shear for steel strip and the like

ABSTRACT

A floating shear arrangement comprises a first knife assembly mounted for movement toward a variable path of material to be cut, and a second knife assembly mounted for movement toward the material path and toward the first knife assembly. An arrangement is coupled to the knife assemblies for drawing the knife assemblies toward one another and toward the material path. The arrangement and the knife assemblies are disposed, such that one of the knife assemblies is moved initially into engagement with the material to establish a shearing location within a range of such shearing locations, and thereafter the other knife assembly is moved into shearing engagement with the material and the one knife assembly.

1451 Sept. 25, 1973 United States Patent Campbell SHEAR FOR STEEL STRIPAND THE LIKE Primary ExaminerFrank T. Yost [75] Inventor. Allen B.Campbell, Pittsburgh, Pa. Atmmey D0nn J- Smith Mesta Machine Company,Pittsburgh, Pa.

May 19, 1972 Appl. No.: 255,004

[73] Assignee:

A floating shear arrangement comprises a first knife as- ABSTRACT [22]Filed:

sembly mounted for movement toward a variable path of material to becut, and a second knife assembly mounted for movement toward thematerial path and toward the first knife assembly. An arrangement iscoupled to the knife assemblies for drawing the knife assemblies towardone another and toward the material path. The arrangement and the knifeassemblies are disposed, such that one of the knife assemblies is movedinitially into engagement with the material to establish a shearinglocation within a range of such [56] References Cited UNITED STATESPATENTS shearing locations, and thereafter the other knife as- 83/600 Xsembly is moved into shearing engagement with the material and the oneknife assembly.

8 Claims, 3 Drawing Figures 83/600 X Petros et 83/557 .K m e m MC 3765556 9999 1111 2605 0262 54 39 .9 9 O3 74 5 56, 2 2223 SHEAR FOR STEELSTRIP AND THE LIKE The present invention relates to a compact sheararrangement for a strip mill or the like and more particularly to ashear of the character described having floating shear components foradjustment to the angle of strip entry.

Throughout the steel industry strip shears and the like are employed inconnection with rolling mills. Shearing of the continuous ribbon orstrip in a rolling mill usually is done for one of a variety of reasons.For example, part of a strip coil containing damaged or offgaugematerial may have to be removed. Large coils are frequently cut intosmaller coils for custom orders. The strip may have to be cut beforeentering the mill owing to cobbling or other equipment malfunction.

Present forms of rolling mill shears normally are located in thevicinity of the mill stand housing. Such locations, however, do notallow adequate access for inspection, servicing and maintenance of theshear. When employed as a cobble shear, conventional shears cause thestrip to pile up in front of the shear at a nearly inaccessable locationfor removal. Previous shears utilize a relatively large number ofcomponent parts, with attendent manufacturing difficulties and excessivemaintenance.

Most importantly, known forms of rolling mill shears are not capable ofcutting the strip at a location in its natural path. That is to sayprior shears do not adjust automatically to the particular path of thestrip, which may be variable. For example a most accessible location forcutting the strip is prior to the tension bridle on the entry side ofthe mill. At this location the path of the strip is continuouslychanging, as the entry strip coil is paid out. However, conventionalshears cannot be located here but located downstream of the tensionbridle where the strip follows a more or less constant pass line. Atthis location the shear is relatively inaccessible as mentionedpreviously.

In accordance with my present invention l provide a floating shear formill strip and the like which unexpectedly and almost instantaneouslyadjusts to a changing path of the moving strip, as the entry coil ispaid out. This essentially automatic adjustment in the floating shear ofthe invention eliminates the need for a constant strip or material passline. The shear of the invention is more compact with fewer parts whichlessens manufacturing difficulties and reduces maintenance. The locationof the novel shear at the mill entry bridle allows convenient access forinspection, servicing and maintenance. When employed as a cobble shear,the strip inevitably piling up in front of my novel shear is in acompletely accessible location for easy removal.

I accomplish these desirably results and overcome the difficulties withthe prior art by providing a floating shear arrangement comprising afirst knife assembly mounted for movement toward a variable path ofmaterial to be cut, a second knife assembly mounted for movement towardsaid path and toward said first knife assembly, means coupled to saidknife assemblies for drawing said knife assemblies toward one anotherand toward said path, said means and said knife assemblies beingdisposed such that one of said knife assemblies is moved initially intoengagement with said material to establish a shearing location within arange of such shearing locations and thereafter the other of said knifeassemblies is moved into shearing engagement with said material and saidone knife assembly.

I also desirably provide a similar shear including means for mountingeach of said knife assemblies for rotation about a common pivotstructure.

I also desirably provide a similar shear wherein said moving meansinclude a prime mover rigidly mounted on one of said knife assembliesand operatively connected to the other of said assemblies throughpivoted linkage.

I also desirably provide a similar shear wherein said knife assembliesare disposed about said common pivot line such that said other knifeassembly is subject to greater inertial forces at least to aid ininducing initial movement of said one knife assembly.

During the foregoing discussion, various objects, features andadvantages of the invention have been set forth. These and otherobjects, features and advantages of the invention together withstructural details thereof will be elaborated upon during theforthcoming description of certain presently preferred embodiments ofthe invention and presently preferred methods of practicing the same.

In the accompanying drawings I have shown certain presently preferredembodiments of the invention and have illustrated certain presentlypreferred methods of practicing the same wherein:

FIG. 1 is a partial front elevational view of one form of strip sheararranged in accordance with my invention;

FIG. 2 is a partial top plan view of the shear as shown in FIG. 1 and ispartially sectioned along reference line IIII of FIG. 3; and

FIG. 3 is a cross-sectional view of the shear as shown in FIG. 1 andtaken along reference line III-III thereof.

Referring now more particularly to the drawings, the exemplarymodification of the strip shear 10 illustrated therein comprises anupper knife assembly 12 and a lower knife assembly I4. The knifeassemblies 12 14 are mounted for rotations about a common pivot line 36at which is mounted in this example a pair of stub shafts 16, 18. Theshafts are stationarily mounted on bridle frame plates 20, 22. Alsomounted on the bridle frame 20, 22 are entry tension rolls 24, 26, inthe conventional fashion.

In the illustrated embodiment each of the stub shafts 16 or 18 isprovided with a pair ofjournals 28, 30. The lower blade assembly 14 ismounted on the stub shaft journals 28 by connection to a pair of bearinghousings 32 (FIGS. 1 and 2) such that the lower knife assembly pivotsabout the center line of the stub shafts 16, 18. In like manner theupper blade assembly 12 is rotatably mounted on journals 30 of the stubshafts 16, 18 by bearing housings 34 (FIG. 2). Thus, the knifeassemblies 12, 14 are rotatably mounted on the same stub shafts forpivotal movement about the common center line 36 (FIGS. 1 and 2). Eachof the bearing housings 32, 34 include suitable and conventional bearingarrangements for anti-frictional purposes, as shown more particularly inthe sectioned portions of FIG. 1.

A conventional shear blade 38 is mounted on the upper knife assembly 12,for example by means of mounting bolts 40. A mating knife blade 42 issimilarly mounted on the lower knife assembly 14. When the upper andlower knife assemblies 12, 14 are pivoted together the knife blades 38,42 mate in the usual fashion to shear strip material or the like caughttherebetween. The particular movements of the knife assemblies I2, 14 inmaking such shearing cuts are described more fully below.

As better shown in FIG. 3 the floating shear 10 of the invention ispositioned on the entry bridle frame members 20, 22 upstream rather thandownstream of the entry of the strip between the lower tensioning roll26 and idler roll 44. Although this represents the most accessiblelocation for the shear of the invention, a problem is created forconventional shears in that the path of the incoming strip iscontinuously varying between a maximum angle approach denoted by arrow46 and a minimum angle approach denoted by arrow 48. Such problem iscreated by the absence of a constant pass line 23 such as occursdownstream of the upper tension bridle roll 24. This problem is solvedin a surprising manner by the present invention, in that the floatingstrip shear 10 can adjust automatically to the angle of strip approach(arrows 46, 48).

In furtherance of this purpose a pair of operating cylinders 50, 52 orother suitable motive means are mounted on one of the floating knifeassemblies 12, 14, in this example on the lower knife assembly 14. Theassembly 14 is provided with a pair of mounting plates 54, S6 for thispurpose on which the cylinders 50, 52 are flange-mounted respectively.Piston rods 58, 60 are pivotally connected to the upper knife assembly12, for the purpose of drawing the knife blades 38, 42 together for theshearing operation. A pair of the cylinders 50, 52 are mounted as shownadjacent the ends of the lower knife assembly 14 for balancedapplication of operating forces. It will be understood however that adifferent number of operating cylinders can be employed depending uponthe application of the invention.

In the arrangement shown, each of the piston rods 58, 60 terminates in aclevis 62 (FIGS. 1 and 3) which is in turn pivotally connected topivoted link 64 in turn pivoted to the bearing housing 34 of the upperknife assembly 12. This double pivot arrangement permits the operatingcylinders 50, 52 and their pistons to adapt to the rotation of the knifeassemblies 12, 14, as the cylinders proper are rigidly joined to thelower knife assembly 14. It will be understood of course that variousoperating linkages can be made between the knife assemblies 12, 14 inkeeping with the broad concepts of the invention.

In operation, activation of the operating cylinders 50, 52 retract thepivoted linkages 62, 64 including piston rods 58, 60 to pivot the knifeassemblies 12, 14 toward one another upon the proper juxtaposition ofthe knife blade 38, 42. The desired shearing action is attained, and aclean and complete cut is made on the strip that passes from pay outcoil 66 or 66' at a varying angle (arrows 46, 48) between the upper andlower knife assemblies 12, 14, i.e. through throat 70 of the floatingshear 10. As mentioned previously as the entry coil 66 or 66' is paidout the strip approach angle to the shear l varies (arrows 46, 48). Theparticular limits of variation as shown in FIG. 3 are purely exemplaryand in no way indicate actual or physical limitations, which will varydepending upon the structure of the shear 10, the initial size 66 andfinal size 66 of the entry coil, and its distance from the shear 10.

The most important consideration is the ability of the shear to adaptautomatically to the continuously changing strip approach. Under normaloperating conditions, the upper knife assembly will be pivoted underimpetus of the one or more operating cylinders 50, 52, until the upperblade 38 pivots into contact with the moving strip. The strip tensionwill resist further rotation of the upper knife assembly 12. During thisinitial movement of the upper knife assembly 12 into contact with themoving strip, the lower knife assembly 14, owing to its dispositionabout the common pivot line 36 (stub shafts l6, 18) will remainstationary under influence of gravity or other inertial forces. However,following the initial movement of the upper knife assembly 12 intocontact with the moving strip and its restraint thereby, the lower knifeassembly 14 then pivots toward the strip and the upper knife assembly 12retained thereby to make the shearing cut.

Inasmuch as the lower knife assembly 14 remains more or less motionlessuntil the upper knife assembly essentially completes its movement to thevariable shearing location, the moving components of the shear 10 alwaysadjust themselves quickly and automatically to the particular angle ofstrip approach when the shearing cut is made. Although described asdiscrete movements of the upper and lower knife assemblies 12, 14 it isto be understood that the prepositioning of the upper knife assembly 12and the subsequent shearing motion of the lower knife assembly 14 areproduced by a single operational movement of the operating cylinders 50,52, including their piston rods 58, 60 and associated pivoted linkages.

It will be noted also that the amount of preliminary positioningmovement of the upper knife assembly 12 will vary from almost nil toalmost the full extent of the throat opening of the shear 10 dependingon whether the strip approach is at or near the maximum angle (arrow 46)or the minimum angle (arrow 48) respectively, as dictated, of course, bystructural limitations in a given embodiment. In any event, the strip isquickly and efficiently sheared irrespective of the particular point inthe rotative paths of the blade assemblies l2, 14 at which the shearblades 38, 42 mate for shearing action.

Desirably stop means 72, 74 are disposed on at least one of the framemembers 20, 22 for determining respectively the initial or startingpositions of the blade assemblies 12, 14 (FIG. 3). Location of the stopmeans 72, 74 is determined by the desired maximum throat opening 70between the shear blades 38, 42. The maximum throat opening 70 will, ofcourse, be determined by the range of strip approaches or pathvariations (arrows 46, 48) in a given application of the invention.

From the foregoing it will be seen that a novel and efficient shear forsteel strip and the like has been described herein. The shear is capableof making cuts in the strip at an advantageously accessible location, incontrast to prior apparatus. The described apparatus is susceptible ofsemiautomatic or completely automated operation as desired. Thedescriptive and illustrative materials employed herein, therefore, areutilized for purposes of exemplifying the invention and not inlimitation thereof. Numerous modifications of the invention will occurto those skilled in the art without departing from the spirit and scopeof the invention. It is to be understood that certain features of theinvention can be used to advantage without a corresponding use of otherfeatures thereof.

I claim:

l. A floating shear arrangement comprising a first knife assemblymounted for movement toward a variable path of material to be cut, asecond knife assembly mounted for movement toward said path and towardsaid first knife assembly, means coupled to said knife assemblies fordrawing said knife assemblies toward one another and toward said path,said means and said knife assemblies being disposed such that one ofsaid knife assemblies is moved initially into engagement with saidmaterial to establish a shearing location within a range of suchshearing locations and thereafter the other of said knife assemblies ismoved into shearing engagement with said material and said one knifeassembly.

2. The combination according to claim 1 including means for mountingeach of said knife assemblies for rotation about a common pivotstructure.

3. The combination according to claim 2 wherein said moving meansinclude a prime mover rigidly mounted on one of said knife assembliesand operatively connected to the other of said assemblies throughpivoted linkage.

4. The combination according to claim 2 wherein said pivot structureincludes a pair of opposed stub shafts, and said blade assemblies aremounted respectively on bearing arrangements disposed longitudinally ofsaid shafts.

5. The combination according to claim 2 wherein stop means are disposedadjacent said pivot line for engagement by said knife assemblies todetermine the maximum throat opening thereof.

6. The combination according to claim 2 wherein said knife assembliesare disposed about said common pivot line such that said otherknifeassembly is subject to greater inertial forces at least to aid ininducing initial movement of said one knife assembly.

7. The combination according to claim 1 wherein said other knifeassembly is subjected to greater inertial forces relative to said oneknife assembly at least to aid in inducing initial movement of said oneknife assembly.

8. The combination according to claim 7 wherein said other knifeassembly is disposed at a lower elevation than that of said one knifeassembly such that said other assembly is subjected to greatergravitational forces for the purpose stated.

1. A floating shear arrangement comprising a first knife assemblymounted for movement toward a variable path of material to be cut, asecond knife assembly mounted for movement toward said path and towardsaid first knife assembly, means coupled to said knife assemblies fordrawing said knife assemblies toward one another and toward said path,said means and said knife assemblies being disposed such that one ofsaid knife assemblies is moved initially into engagement with saidmaterial to establish a shearing location within a range of suchshearing locations and thereafter the other of said knife assemblies ismoved into shearing engagement with said material and said one knifeassembly.
 2. The combination according to claim 1 including means formounting each of said knife assemblies for rotation about a common pivotstructure.
 3. The combination according to claim 2 wherein said movingmeans include a prime mover rigidly mounted on one of said knifeassemblies and operatively connected to the other of said assembliesthRough pivoted linkage.
 4. The combination according to claim 2 whereinsaid pivot structure includes a pair of opposed stub shafts, and saidblade assemblies are mounted respectively on bearing arrangementsdisposed longitudinally of said shafts.
 5. The combination according toclaim 2 wherein stop means are disposed adjacent said pivot line forengagement by said knife assemblies to determine the maximum throatopening thereof.
 6. The combination according to claim 2 wherein saidknife assemblies are disposed about said common pivot line such thatsaid other knife assembly is subject to greater inertial forces at leastto aid in inducing initial movement of said one knife assembly.
 7. Thecombination according to claim 1 wherein said other knife assembly issubjected to greater inertial forces relative to said one knife assemblyat least to aid in inducing initial movement of said one knife assembly.8. The combination according to claim 7 wherein said other knifeassembly is disposed at a lower elevation than that of said one knifeassembly such that said other assembly is subjected to greatergravitational forces for the purpose stated.